Method for cold-rolling grating workstock

ABSTRACT

A method of forming grating material from elongated, generally flat workstock, comprising the steps of cold-forming a series of adjacently oriented notches or recessed portions along at least one edge of the workstock by peripherally engaging a rotatable externally ribbed or toothed roller element with the workstock, and thereafter passing the workstock between a plurality of spaced rollers and thereby straightening and flattening the workstock, and finally cutting the workstock into preselected lengths preparatory to assembling the same into a unitized grate structure.

United States Patent Tislrken 1 Mar. 7, 1972 4 [54] METHOD FORCOLD-ROLLING GRATING WORKSTOCK [72] Inventor: Paul Tishken, Birmingham,Mich.

[73] Assignee: Tishken Products (30., Detroit, Mich.

[22] Filed: Apr. 8, 1969 [21] Appl. No.: 814,289

[52] US. CL ..72/187, 72/197, 72/198 [51] Int. ..B2lh 8/00 [58] FieldofSearch ..72/184, 196, 197, 198, 190,

[56] References Cited UNITED STATES PATENTS 375,746 H1883 Harris1,773,836 8/1930 Woelfel ..72/198 2,911,865 11/1959 Brickman ...72/1981,636,592 7/1927 Cushwa ..29/160 1,678,362 7/1928 Sloan ..29/160 FOREIGNPATENTS OR APPLICATIONS 1,072,925 6/1967 Great Britain ..72/197 PrimaryExaminer-Lowell A. Larson Att0rneyI-Ia.rness, Dickey & Pierce [57]ABSTRACT A method of forming grating material from elongated, generallyflat workstock, comprising the steps of cold-forming a series ofadjacently oriented notches or recessed portions along at least one edgeof the workstock by peripherally engaging a rotatable externally ribbedor toothed roller element with the workstock, and thereafter passing theworkstock between a plurality of spaced rollers and therebystraightening and flattening the workstock, and finally cutting theworkstock into preselected lengths preparatory to asembling the sameinto a unitized grate structure.

9Claims,8DrawingFigures PATENTEDMAR 71912 a, 646,794

SHEET 1 UF 3 HI! IIHIHLTJ IN VEN TOR ATTORNEY PAIENTEBMAR 7 I972 SHEET 2UF 3 INVENTOR ATTORNEY METHOD FOR COLD-ROLLING GRATING WORKSTOCKBACKGROUND OF THE INVENTION Grating structures, such as are commonlyutilized in tire escapes, sidewalk, and sewer grates, and the like,consist of a grid of spaced parallel metal strips arranged on edge andoriented such that a certain number of the strips are disposed atapproximately right angles to others thereof, with any suitable jointbeing provided at the intersection of the series of strips. While suchgrating constructions have been found extremely useful for manyapplications, it has been found desirable to provide the upper sidesthereof with a nonskid surface to minimize the possibility of a personinadvertently slipping or sliding thereon in the event water, ice, snow,or the like accumulates on the upper side of the grates. While a numberof so-called nonskid surface designs have been heretofore proposed toobviate such slipping and/or sliding problems, it has been found thatone of the most effective nonskid surfaces can be achieved by forming aseries of notches or recessed portions along the upper edges of thestrips making up a grating structure, which notches provide or define aplurality of biting edges arranged transversely of the strips andadapted to increase the frictional characteristics between the upperside of the structure and, for example, the sole of the shoe, boot orthe like of a person walking thereon.

In order to provide the aforesaid notches or recessed portions in thestriplike grating workstock which constitute the majority of gratingstructures, it has heretofore been the practice to pass preheated stripsof workstock through or adjacent a reciprocating cutter or die whichfunction to cut a series of longitudinally spaced notches or recesses inthe material. While this procedure has been found to be the bestavailable technique for forming the nonskid notches in the workstock,such a technique has been objectionable for a number of reasons. Firstof all, such a procedure produces vast quantities of metal chips which,for most purposes, are waste material that cause considerable problemsin handling and disposition, to say nothing of the expenses involved inthe wasted material itself. Another objectionable feature of the abovedescribed method of fonning the notches or recesses in the gratingworkstock resides in the expenses involved in heating the workstockpreparatory to subjecting the same to the reciprocating notch-formingdie or cutting tool.

In accordance with the principles of the present invention, a new andimproved apparatus is provided for forming grating material which isprovided with the aforesaid nonskid notches or recessed portions alongeither one or both edges thereof. More particularly, the presentinvention utilizes a cold-rolling operation consisting of passing thestrip grating material adjacent a rotatable tool having a plurality ofcircumferentially spaced, outwardly projecting portions adapted to beforced inwardly into the workstock and thereby form the notches orrecessed portions therein, the workstock thereafter passing through anassociated straightening and flattening means to remove anyeccentricities or curvatures in the workstock that may be produced uponforming the notches therein. Such a cold-fonning operation has beenfound to be a considerable advance over the above described practice offorming the notches by means of initially preheating the workstock andthereafter subjecting the same to the action of a reciprocating cuttingtool or die, since the cold-forming technique entirely obviates theproduction of any metal chips, the ancillary problems of disposing ofsuch chips, as well as the need for heating the workstock prior toforming the notches therein.

Certain additional advantages of the present invention reside in thefact that the notched or recessed grating workstock produced inaccordance therewith will be found to be substantially stronger as aresult of the cold-rolling operation, as compared with similar workstockthat has heretofore been produced by initially heating the workstock andthereafter cutting the notches therein with a reciprocating tool. It isestimated that the structural integrity of the workstock is increased asmuch as 10-20 percent as a result of the coldrolling operation, whichpermits the use'of a smaller number of strips of grating material tosupport a given load per unit of area. Moreover, as a result of thecold-forming operation, the workstock has been found to be elongated asmuch as approximately 1 inch per foot, with the result that a givenlength of strip workstock will produce an even greater length of gratingworkstock as a result of the notches or recesses being formedthereinpursuant to the teachings of the present invention. Additionally,the actual formation of the nonskid-notches can be performed at aconsiderably fast rate than has been possible with heretofore known andused methods, thereby substantially increasing the production rate ofsuch grating workstock.

SUMMARY OF THE INVENTION This invention relates generally to a new andimproved method of fabricating metal workstock, and more particularly,to a new and improved method of fabricating metal grating material.

It is accordingly a general object of the present invention to provide anew and improved method of forming grating workstock.

It is a more particular object of the present inventionto provide amethod of cold-rolling nonskid notches or recessed portions in gratingworkstock. I

It is another object of the present invention to provide a method of theabove character which includes the steps of forming the notches orrecessed portions in the grating workstock by passing the workstockadjacent a rotatable element having outwardly extending projectionsadapted to be forced into the workstock and thereby form the nonskidnotches or recesses therein.

It is a further object of the present invention to provide a method ofthe above character which includes the steps of forming the series ofnonskid notches or recessed portions simultaneously along the oppositeedges of the workstock.

It is yet another object of the present invention to provide a new andimproved method of cold fonning grating workstock which includes thesteps of flattening, straightening, and automatically cutting offpreselected lengths of the workstock subsequent to the nonskid notchesor recessed portions being formed therein.

Other objects and advantages of the present invention will becomeapparent from the following detailed description taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF 'II-IE DRAWINGS FIG. 1 is an elevated perspectiveview of a typical grating structure adapted to be manufactured inaccordance with the method of the present invention;

FIG. 2 is an enlarged fragmentary elevated perspective view of a portionof the grating structure shown in FIG. 1;

FIG. 3 is an elevated perspective view of a portion of the apparatusutilized in practicing the method of the present inventron;

FIG. 4 is a side elevational view of the portion of the apparatus of thepresent invention located at the right end of the structure shown inFIG. 3;

FIG. 5 is a side elevational view of a notch-forming roller andassociated drive means incorporated in practicing the present invention;

FIG. 6 is a top elevational view, partially schematic, of the roller andassociated backup rollers incorporated in the present invention;

FIG. 7 is a view similar to FIG. 6 and illustrates an alternateembodiment of the present invention, and

FIG. 8 is a transverse cross-sectional view taken substantially alongthe line 8-8 of FIG. 7.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT I Referring now in detailto the drawings, FIGS. 1 and 2 illustrate a typical grate structurewhich may be provided with an external frame or the like 12 andcomprises a series of spaced parallel strips of grating workstock,generally designated 14, which strips 14 are arranged in perpendicularlyoriented transverse and longitudinally arranged rows which intersect,via lap joints or the like, as best seen in FIG. 2.

The strips of grating workstock 14, in a typical construction of thegrate structure 10, are fabricated of cold-rolled steel or the like andare provided with a series of adjacently oriented inwardly projectingnotches or recessed portions, generally designated 16 that function toenhance the frictional charac teristics of the upper surface of thestructure 10 whereby to provide a nonskid surface upon which people maytraverse without slipping, falling, or otherwise endangering themselves.The present invention deals particularly with a new and improved methodfor forming the nonskid notches, as will hereinafter be described indetail.

Generallyspeaking, the apparatus of the present invention consists of afeeding station 18 which provides a source of the grating workstock 14to be notched, a notch forming station 20 into which the workstock 14 isfed and which performs the notch-forming operations hereinafter to bedescribed, a workstock straightening and flattening station, generallydesignated 22, adapted to receive the workstock 14 from the station 20,and finally a workstock cutoff station 24 which takes the workstock 14after it has been straightened and flattened via the station 22 and cutsit off into preselected segmental lengths preparatory to assemblythereof into a suitable grate structure such as the structure 10.

Referring now in detail to the workstock-notching station 20, asillustrated in FIGS. 5 and 6, the station 20 is provided with a suitabledrive motor or the like 26, that may be energized by any suitable sourceof electrical or hydraulic power, and has an output shaft 28 that isdrivingly connected through a suitable gearbox or transmission 30 andshaft 32 to a pinion gear 34. The gear 34 is meshingly engaged with aprimary drive gear 36 which is mounted at one end of a drive shaft 38that is rotatably supported by a suitable antifriction means (not shown)in an appropriate support structure, representatively designated by thenumeral 40. The end of the shaft 38 opposite that-which is connected tothe gear 36 is provided with a suitable worm gear 42 that is drivinglyengaged to an associated drive gear 44 which is mounted on the lower endof a generally vertically disposed shaft 46. The support structure 40may be of any suitable construction adapted to support the various gears34, 36, 42, and 44, as well as the shafts 28, 32, 38, and 46 in anefficient, compact, and operativeconfiguratron.

The shaft 46 is adapted to rotatably support a generally cylindricallyshaped notch forming element 48 which is adapted to perform a coldrolling or working operation upon the grating workstock 14 and therebyfonn the series of nonskid notches 16 therein. More particularly, theelement 48 comprises a generally cylindrically shaped body section 50defining a central vertically extending bore 52 within which .the upperend of the shaft 46 is received and drivingly connected to the element48. The outer periphery of the element 48 is formed with a plurality ofequally circumferentially spaced, vertically or axially extendingoutwardly directed notched fonning projections or riblike teeth 54 whichpreferably extend along the entire length of the element 48. Preferably,the axial length (height) of the element 48 is several times thethickness of the workstock 14, for purposes laterto be described. Asbest seen in FIG. 6, the notch-forming teeth 54, in transverse section,are generally trapezoid shaped and have a generally axially extendingouter surface portion 56 and inwardly diverging face portions 58 and 60.As will be described in detail, in operation of the notch-formingstation 20, the teeth 54 are adapted to peripherally engage one edge ofthe grating workstock 14 and thereby cold-form the notches 16 therein.

As best illustrated in FIG. 5, disposed adjacent the notch formingelement 48 is a backup roller assembly, generally designated 62, whichcomprises a suitable support structure having upper and lower sections64 and 66 adapted to support a suitable rotatable shaft 68 in generallyspaced parallel relation with respect to the shaft 46. The shaft 68 isprovided with a backup roller member 70 which is generally cylindricallyshaped and defines an annular, radially inwardly extending guide recess72 around an intermediate portion thereof. The axial width of the recess72 is adapted to be slightly-greater than the thickness of the workstock14, whereby one edge of the workstock 14 may be received therein andthereby guided in peripheral relation with respect to the notch-formingelement 48, as shown in FIG. 6. It will be seen that the shaft 68 isspaced radially away from the shaft 46 a preselected distance such thatthe space between the radially innermost portion of the recess 72 andthe outer periphery of the bodysection 50 of the element 48 isapproximately equal to the width of the workstock 14, so as to assurethat the workstock 14 will be positively peripherally engaged with theelement 48 as the notches 16 are formed therein by the teeth 54.

A particular feature of the above invention resides in the fact thatmeans may be provided on either one or bothof the, shafts 46, 68 formoving the roller assembly 62 and/or element 48 axially of itsrespective supporting shaft. Such means maybe provided'by one or morelarge washers or spacing disks 74 disposed between the upper and lowerends of the assembly 62 and element 48 and the adjacent supportstructure rotatably supporting the shafts 46, 68. The purpose of such adesign is to permit the workstock 14 to selectively peripherally engagethe element 48 at different axial positions thereon, whereby to equalizetool wear after continued use of the apparatus of the present invention.More particularly, it will be seen that if one or more spacers areprovided beneath the lower side of the assembly 62 and/or above theelement 48, the annular guide recess 72 will be located relativelycloser to the upper end of the element 48, whereby when the workstock 14is passed interjacent the recess 72 and element 48, it will peripherallyengage the element 48 adjacent the upper end thereof. Similarly, if oneor more of the spacing disks 74 are provided adjacent the upper end ofthe roller member 70 and/or at the lower end of the element 48, theannular guide recess 72 will be axially disposed relatively closer tothe lower end of the element 48 so that as the workstock 14 is guidedthereby, it will be engaged with the lower end of the element 48. Thus,by properly incrementally axially adjusting or positioning the assembly62 and/or element 48 along the shafts 68, 46 through proper selectionand periodic changing of the spacing disks 74, the workstock 14 can bemade to engage the element 48 at different axial locations thereon sothat relatively uniform wear of the element 48 may be achieved, thusmaximizing tool life. It will be apparent,-of course, that variousalternatemeans may be used for selectively adjusting the axialrelationship or relative axial positioning of the annular guide recess72 with respect to the element 48, such as by providing some type ofaxial adjustment means on the shafts 46, 68, as will be apparent tothose skilled in the art.

In a preferred construction of the present invention, two pairs of guiderollers 76, 78 and 80, 82 are provided adjacent the forward and rearwardsides of the element 48 and roller assembly 62, which guide rollers areprovided upon suitable vertically extending shafts 84, 86 and 88, 90,respectively, whereby to assure proper orientation of the workstock 14as it passes toward and away from engagement with the notchformingelement 48. If desired, one or more of the pairs of rollers 76, 78 or80, 82 may be rotatably driven whereby to push or pull the workstock 14through the notch-forming station 20. Also, such rollers 76-82 may beformed with radially inwardly extending recesses such as the guiderecess 72 to assist in axially aligning the workstock 14 with respect tothe element 48, provided, however, that such guide recesses do notimpair relative axial positioning of either the element 48 or backuproller assembly 62 pursuant to the above-described feature minimizingtool wear on the element 48. If desired, horizontally disposed rollers(not shown) may be provided adjacent the guide rollers 76, 78 and 80, 82for positioning the workstock 14 axially of the element 48.

Referring now to the construction of the workstock feeding station 18,as best seen in FIG. 4, the station 18 comprises a base or supportstructure 92 adapted to support an upwardly extending pedestal '94 uponwhich a suitable horizontally disposed support shaft 96 is mounted. Theshaft 96 is adapted to support a suitable reel or coil of the workstock14, representatively designated by the numeral 98, and be provided withsuitable radially outwardly projecting coil-supporting arms 100 adaptedto operatively support the workstock roll or coil 98, for example, inthe manner disclosed in US. Pat. No. 3,022,024, issued Feb. 20, 1962 tothe applicant. Suitable braking or clutching means may be provided inthe feeding station 18 for preventing rotational momentum of theworkstock coil 98 from building up upon rotation thereof, and therebycontrol selective feeding of the workstock 14 into the notch-formingstation 20.

After the workstock 14 has been conveyed from the feeding station 18into the station 20, wherein the series of notches or recessed portions16 are formed therein, the workstock 14 progresses or is conveyed to thestraightening and flattening station 22 which may be of any suitableconventional construction and preferably comprises one or morelongitudinally spaced workstock flattening assemblies, generallydesignated 102, that are supported on a generally horizontally extendingsupport surface 104 defined by a suitable support or base structure 106.Each of the assemblies 102 comprises suitable roller support means,generally designated 108, adapted to operatively support upper and lowercooperative pairs of rollers 110 and 112, respectively, for rotationabout vertically spaced, horizontally extending support shafts or thelike (not shown). Suitable means, representatively designated 113, ispreferably provided for selectively adjusting the relative proximatepositions of the upper rollers 110 with respect to the lower rollers 112of each of the assemblies 102, whereby to selectively control and adjustthe applied pressure exerted by the rollers 110, 112 upon the workstock14 which passes therebetween in order to effect flattening of theworkstock 14, as is well known in the art.

Disposed adjacent the outlet" sides of the flattening assemblies 102 area plurality of workstock-edging assemblies 114 which may be of anysuitable construction and are preferably provided with laterally spacedpairs of rollers 116 rotatable upon vertical extending axes and adaptedto have the workstock 14 pass therebetween so as to apply laterallyinwardly directed forces thereon to control the conformation or shape ofthe laterally opposite edges thereof, as is well known in theroll-forming art. The need for such edging assemblies 114 resultsprimarily from the fact that the original coil 98 of workstock 14 isfrequently considerably wider than the strips that are subjected to thenotch forming operations, and that the edges of the strips of workstockbecome out of square when they are cut from the original coils 98,thereby necessitating the assemblies 114 for cold-forming the workstock14 into the desired symmetrical or rectangular configuration.

In a preferred construction of the present invention, the end of thesupport structure 106 adjacent the notch-forming station is providedwith suitable guide roller assembly 118 comprising a pair ofhorizontally extending, vertically spaced rollers 120 adapted to guidethe workstock 14 as it passes from the station 20 into the adjacentflattening assembly 102. Disposed at the opposite end of the supportstructure 106 from the assembly 118 is a workstock-straighteningassembly 122 comprising an elevated support structure 124 adapted tooperatively support a plurality of horizontally extending upper rollers126. The assembly 122 also comprises a lower roller support structure128 which supports a plurality of lower rollers 130 that are spacedbelow and in staggered relation with respect to the upper rollers 126,as is illustrated in FIG. 3. The construction and operation of theworkstock-straightening assembly 122 is well known in the art and adetailed description thereof will be omitted for purposes of simplicityof disclosure, it being apparent that the workstock 14 is designed topass between the upper rollers 126 and lower rollers 130 and thereby beaccurately straightened as a result of the interaction of the rollers126, 130 thereon.

Disposed adjacent the assembly 122 is a workstock cutoff assembly,generally designated 132, which is adapted to have the workstock 14 passtherethrough and be cut into segmental sections of predetermined length.The assembly 132 may be of any suitable construction, such as theconstruction described in US. Pat. No. 3,1 1 1,054, issued Nov. 19, 1963to the applicant, although various alternate constructions will beapparent to the skilled artisan. After the workstock passes through theassembly 132, it passes between a pair of extraction rollers 134 and 136which may be suitably powered so as to pull the segmental sections ofthe workstock 14 away from the cutoff assembly 132 at a relativelyfaster rate than the workstock 14 is conveyed thereto, whereby toprevent any interference between successive workpieces being out off bythe assembly 132. From the extraction rollers 134, 136, the segments ofworkstock 14 are adapted to pass onto a runoff table, generallydesignated 138, which is supported adjacent the end of the supportstructure 106 by suitable support pedestals 140. The runoff table 138may be provided with suitable means for periodically dumping orotherwise transferring a plurality of workstock sections thereon onto anappropriate conveyor assembly, pallet, or other workstock transferringmedium after a preselected number of sections have accumulated on thetable 138, as is well known in the art.

In operation, assuming the initial condition that the drive motor 26 isenergized and that the straightening and flattening station 22 isproperly energized, for example through suitable manually actuatablecontrols 142, workstock 14 is initially unreeled from the coil 98 and ispassed between the guide rollers 76, 78. Thereafter, the workstock 14passes between the notch forming element 48 and the backup rollerassembly 62, whereby the series of longitudinally spaced notches 16 arecold formed in the workstock 14 as the projections 54 are successivelyforced inwardly into the adjacent lateral edge of the workstock 14. Asthe projections 54 thus produce the notches 16, a certain amount ofmetal adjacent each of the notches 16 cold-flows or is displaced aboveand below the workstock 14 at each of the notches 16, with the resultthat there is a certain increase in the overall thickness of theworkstock 14 around the edge of each of the notches 16. Moreover, as aresult of forming the notches 16 along one lateral side of the workstock14, the workstock 14 tends to assume a somewhat curvilinearconfiguration.

After the workstock 14 passes between the element 48 and backup rollerassembly 62, it passes between the guide rollers 80, 82 and thereafterbetween the rollers and through the straightening and flattening station22. As the workstock 14 passes through the station 22, it alternatelypasses through the flattening assemblies 102 and the edging assemblies114, whereby the aforesaid curvilinear shape is removed and the enlargedthickness portions of the workstock 14 at the notches 16 are flattenedor removed. Finally, the workstock 14 passes between the straighteningrollers 126, which function to straighten the workstock along the planeof the major width thereof, at which time the workstock 14 passesthrough the cutoff assembly 132 and extraction rollers 134, 136, wherebythe workstock 14 is cut into segmental sections that are transferred tothe runoff table 138. After a certain number of sections of theworkstock 14 have accumulated on the table 138, the same'will beactuated to dispose the workstock sections the case with the workstockl4 processed bythe apparatus shown in FIGS. 5 and 6. In order toaccomplish forming the notches 16 along both edges of the workstock 14,the backup roller assembly 62 is replaced with a notch-forming element48' which may be identical in construction and operation to thehereinabove described element 48 and may be suitably driven by asuitable drive means, representatively designated by the numeral 144,which may be identical in construction and operation to the drive meansprovided by the drive motor 26, transmission 30, and gears 34, 36, 42,and 44, or any other suitable drive mechanism. The'notch formingelements 48, 48' may be rotatably positioned so as to form the notches16 along each side of the workstock 14 so that the notches 16 arelaterally aligned, or alternatively, staggered or alternated, as isshown in FIG. 7, depending upon the particular type of grating structuredesired. A particular feature resulting from the simultaneous forming ofthe notches 16 along both sides of the workstock 14, as compared withforming the notches 16 along only one side thereof, resides in theelimination of the curved configuration that the workstock l4 assumeswhen the notches 16 are formed on one side thereof, thereby obviatingthe need for subsequently laterally straightening the workstock 14.

It will be seen from the above described construction of the presentinvention that a new and improved method and apparatus is provided forcold-rolling nonskid notches within elongated or strip gratingworkstock. A particular feature of the present invention resides in theelimination of the formation and subsequent handling of metallic chipswhich were abundantly produced in the production of grating material onconventional reciprocal cutting machines. Additionally, the presentinvention eliminates the need for preheating the workstock preparatoryto cutting the nonskid notches therein. Also of importance is the factthat cold-rolling the notches 16 in the workstock 14, as well as thecold-working of the workstock 14 as the same is subjected to thestraightening, flattening and edging operations, has been found toconsiderably strengthen the workstock and effect a certain amount ofelongation thereof. Accordingly, the grating workstock produced inaccordance with the present invention will be capable of supporting agreater load than has heretofore been possible with conventionallymanufactured grating material, and a greater amount of grating workstockwill be produced for a given amount of workstock utilized. Anotherfeature of the present invention resides in the fact that the notchforming element 48 (48') and associated backup roller assembly 62 may beselectively axially positioned relative to one another, whereby toreduce wear of the element 48 to a minimum. Moreover, by designing theelement 48 such that it is of a relatively massive (thick) construction,said element will be extremely strong and not be subjected to chippingor other attrition. Additionally, the relative shape and spacing betweenthe notches 16 on the workstock 14 may be varied considerably bychanging the configuration of the notch forming element 48, and

. said notches 16 may be provided along both sides of thegratingworkstock 14 by merely substituting an additional element 48' forthe backup roller assembly 62, as above described, whereby to providefor universality of application.

While it will be apparent that the preferred embodiment illustratedherein is well calculated to fulfill the objects above stated, it willbe appreciated that the present invention is susceptible tomodification, variation and change without departing from the scope ofthe invention.

lclaim:

1. In the method of manufacturing elongated strips of grating materialfrom generally flat, rectangular cross section workstock, the stepswhich include,

successively engaging a plurality of irregular notch forming elements onthe periphery of a rotating member with the workstock and therebyforming a series of adjacently oriented notch portions along one lateraledge of the workstock and simultaneously cold working the workstock tostrengthen the same and effecting preselected elongation of theworkstock, whereby workstock of preselected length produces a recessedgrating workpiece of predetenninately greater length. 2. The method asset forth in claim 1 which includes the step of straightening andflattening the workstock both longitu dinally and laterally by passingthe workstock between spaced I rollers.

of alternatively flattening and straightening the workstock subsequentto forming the notched portions therein.

5. The method as set forth in claim 1 which includes the step ofsimultaneously forming a series of adjacently oriented notched portionsalong the laterally opposite edges of the workstock.

6. The method as set forth in claim I which includes the step of guidingthe workstock into peripheral engagement with the rotating member bypassing the workstock in part through an annular recessed portion formedin a backup roller assembly, which includes the step of straighteningthe workstock both longitudinally and laterally by passing the workstockbetween spaced rollers, and which includes the step of successivelycutting off preselected segmental sections of the workstock after thesame has been straightened and flattened subsequent to formingthenotched portions therein;

7. The method as set forth in claim 6 which includes the step ofsimultaneously forming a series of adjacently oriented notched portionsalong the laterally opposite edges of the workstock.

8. The method as set forth in claim 6 which includes the step ofadjusting the relative axial positions of the backup roller assembly androtatable member, whereby to guide the workstock into peripheralengagement with the rotatable member at different axial locationsthereon.

9. The method as set forth in claim 1 which includes the step offlattening the grating material subsequent to fonning said notchportions therein, whereby the thickness of the notched grating materialis substantially the same as the original workstock.

* i i t

1. In the method of manufacturing elongated strips of grating materialfrom generally flat, rectangular cross section workstock, the stepswhich include, successively engaging a plurality of irregular notchforming elements on the periphery of a rotating member with theworkstock and thereby forming a series of adjacently oriented notchportions along one lateral edge of the workstock and simultaneously coldworking the workstock to strengthen the same and effecting preselectedelongation of the workstock, whereby workstock of preselected lengthproduces a recessed grating workpiece of predeterminately greaterlength.
 2. The method as set forth in claim 1 which includes the step ofstraightening and flattening the workstock both longitudinally andlaterally by passing the workstock between spaced rollers.
 3. The methodas set forth in claim 2 which includes the step of successively cuttingoff preselected segmental sections of the workstock after the same hasbeen straightened and flattened.
 4. The method as set forth in claim 1which includes the step of alternatively flattening and straighteningthe workstock subsequent to forming the notched portions therein.
 5. Themethod as set forth in claim 1 which includes the step of simultaneouslyforming a series of adjacently oriented notched portions along thelaterally opposite edges of the workstock.
 6. The method as set forth inclaim 1 which includes the step of guiding the workstock into peripheralengagement with the rotating member by passing the workstock in partthrough an annular recessed portion formed in a backup roller assembly,which includes the step of straightening the workstock bothlongitudinally and laterally by passing the workstock between spacedrollers, and which includes the step of successively cutting offpreselected segmental sections of the workstock after the same has beenstraightened and flattened subsequent to forming the notched portionstherein.
 7. The method as set forth in claim 6 which includes the stepof simultaneously forming a series of adjacently oriented notchedportions along the laterally opposite edges of The workstock.
 8. Themethod as set forth in claim 6 which includes the step of adjusting therelative axial positions of the backup roller assembly and rotatablemember, whereby to guide the workstock into peripheral engagement withthe rotatable member at different axial locations thereon.
 9. The methodas set forth in claim 1 which includes the step of flattening thegrating material subsequent to forming said notch portions therein,whereby the thickness of the notched grating material is substantiallythe same as the original workstock.